The present invention relates to a film wind-up control apparatus for a camera which can controllably change the length of film to be transported each exposure, and more particularly to a film wind-up control apparatus for a camera which can count down the remaining exposures of a film in the camera according to the change in length of film to be transported.
Cameras, in particular middle-size or large-size cameras for use with wide films, must be made as compact as possible and must give a loaded film the proper tension so as to keep it flat during exposure. For this, there are provided in such cameras a pair of guide rollers so arranged as to guide the film in a zigzag path from a film supply spool to a film take-up spool. In this zigzag path, the film turns sharply about the guide rollers, which have a small diameter. If the film is left in the camera for a long time, the film is apt to develop a permanent curl around the guide rollers. If the permanently curled part of the film is placed in the exposure area, it is hard to flatten it. As a consequence, it often happens that when the camera is left unused for a long period of time, there will be a poorly focused image on the film.
For this reason, if a part of the film is permanently curled, it is desirable to advance this part of the film out of the exposure station of the camera in order to avoid taking a poorly focused picture due to the curled film.
Because the length of the film is fixed, and in the normal case there is a predetermined number of exposures, when the film is occasionally advanced a distance greater than a normal frame, the remaining possible number of exposures left on the film will be changed. As is well known in the photographic art, cameras are provided with exposure counters, which are, however, incapable of indicating the actually remaining possible number of exposures on a film loaded in the camera. When the number of possible exposures indicated is different from the actual number of possible exposures on the film in the camera, there will be difficulties at the end of the roll of film.